NIH Biophysics Seminar A series of experiments using patch clamp capacitance recording has been initiated to further explore the secretion properties of RBL-2H3 cells. The technique makes use of the fact that the cell membrane area is proportional to capacitance, thus allowing measurements of the membrane area. Preliminary experiments have revealed both endocytic steps in capacitance as well as curious spikes possibly due to transient fusion events of exocytotic granules.